“…It may also be caused by motor block following high spinal or extradural blocks; it may occur as a focal effect following retrobulbar block in ophthalmic surgery (Smith, 1982;Hathaway, 1983) or from possible subarachnoid spread following an excessive dose by interscalene brachial plexus block (Lauckner, 1982). Delayed respiratory arrest has been reported 3 h after uneventful extradural administration, as a quasi side effect of bupivacaine (Holmboe and Kongsrud, 1982), but as the patient was fully conscious but totally paralysed, subdural extra-arachnoid spread, which commonly produces a delayed but extensive effect, is a more likely explanation. An increase in extradural pressure may cause transient respiratory depression (Gissen and Leith, 1985).…”